Why Simenon's plot device had to go

Balzac, in his novel The Splendours and Miseries of Courtesans, described him as the "most powerful person in France". To the French detective novel or cop flicks the juge d'instruction is an essential character. Simenon's Inspector Maigret relied on these examining magistrates to provide the necessary stupidity to enable him to demonstrate his astuteness. But the job - created by the Napoleonic code more than 200 years ago - is to be abolished. It is Nicolas Sarkozy's wish, and last Friday an official report to the ministry of justice took the first steps towards granting it.

For the English, the examining magistrate has been at the centre of debate about the merits of the two systems of criminal justice. It provided proof for the enduring yet misguided belief that under the English system an accused is regarded as innocent until proved guilty, whereas under the French he or she is guilty until proved innocent. That is a misunderstanding, often deliberate by English lawyers peddling the boast that English justice is superior to any other.

It arises from the fact that, in English adversarial trials, the prosecution and the defence slug it out like gladiators. The judge makes sure proceedings run smoothly, but the decision as to guilt or innocence (of relatively serious crimes) rests with a jury.

The principle in the inquisitorial system is to have someone whose task it is to sift through the evidence, if necessary to interview suspects, witnesses and police, and come to an independent opinion as to whether the accused should be put on trial. This is not saying that the accused is presumed guilty. In favour of the French system, it gets closer to the truth of the events in question than the English, over-reliant on what emerges from the fight in the courtroom.

Are there more wrongful convictions in France or England? This cannot be answered statistically. I'm sure that if I were guilty, I would choose to be tried in England, where I would have a better chance of being wrongfully acquitted. If I were innocent? A close call.

What finally condemned the examining magistrate was the grotesque misuse of his powers by one young juge d'instruction in Outreau, near Boulogne. On the flimsiest evidence, he kept 13 alleged paedophiles in custody, some for four years. All were innocent, but their lives were ruined and one took his own life. Opponents say abolition would remove the one independent person in the criminal justice process, leaving prosecutors vulnerable to political pressures. Against the Outreau scandal, that argument gains little public support.

It is not yet clear what structure will replace the juge d'instruction but it will clearly be a move towards the principles of the English process. I have already encountered a whiff of triumphalism in the English legal establishment, as if the president's plans are an admission that the English system is, after all, superior.